WASHINGTON — The Department of Veterans Affairs is making strides in tracking veteran suicide, but figuring out how many former servicemembers take their own lives is still largely a guessing game. The latest analysis points to an average of 22 veteran suicides per day in 2010, according to a recently released VA study. That’s up from an estimated 18 each day in 2007.

But the stats are based on an incomplete collection of national data. The VA used death certificates from only 21 states – not including California or Texas, home to the largest population of veterans. Women, as well as young, single veterans, are often missing from the data.

Extrapolating a national average from that limited data is premature, said Rajeev Ramchand, a behavioral scientist at the Rand Corporation, a think tank in Washington.

“It’s too much to make that leap,” said Ramchand, who studies military suicide.

Researchers with the VA study acknowledge the shortcomings and warn that the estimates should be “interpreted with caution.” The conclusions derived from the 21 states “may not be [able to generalize] to the larger veteran population,” the researchers wrote.

This is despite the most comprehensive effort ever undertaken to review veteran suicides.

In 2010, VA Secretary Eric Shinseki asked the states to share their yearly suicide data going back to 1999, and the VA has been combing through the data provided so far by cooperating state governments. Before engaging with the states, the VA’s suicide numbers were limited to veterans who had received health care through the agency, which is only about half of the veteran population.

“This really is a big step forward,” Ramchand said.

And despite the incomplete picture, Paul Rieckhoff, executive director of Iraq and Afghanistan Veterans of America, said the report supports what they’ve known anecdotally.

“It underscores how we have a serious veteran suicide problem and it cuts across generations,” he said.

Among the 21 states in the study -- included simply by virtue of being the first states to turn over their data -- the VA found more than 27,000 veterans committed suicide from 1999-2012. Veteran suicides accounted for 18 percent of the 147, 000-plus suicides in those states.

However, death reporting varies from state to state, and not every state marks whether a decedent served in the military, according to the Center for Disease Control and Prevention. Even among the 21 states in the study, not every one reported veteran status for every year. As a result, the VA tossed 34,000 known suicides because military service data on the death certificates was incomplete. That’s 23 percent of the total suicides that the VA couldn’t include in its analysis.

“It really highlights the fact that our knowledge and data on suicide really falls short nationally,” Ramchand said, noting the latest numbers are from 2010. “How do we identify if suicide is increasing or decreasing when working with 3-year-old data? It’s hard to respond accurately.”

The newest generation of veterans -- those who served in Iraq and Afghanistan -- are likely to be among the ones missed in the suicide data.

To check the reliability of using death certificates to track veteran suicides, the VA matched the records they received from Washington state with their own records. Researchers found that nearly one in three female veterans lacked military service data in their state paperwork, and “younger or unmarried veterans and those with lower levels of education were also more likely to be missed on the death certificate.”

The agency is just beginning to have the data to understand the trends among different demographics. For example, the early data shows that the percentage of veteran suicide varied across regions, from about 7 percent to 26 percent -- something the VA said it will study further to explain.

“We really have very little research around what causes vets to take own lives and what stops it,” Rieckhoff said.

The problem of veteran suicide needs to be tackled by a number of different entities, like spokes on a wheel, he said, naming colleges, religious groups, the VA and veteran service organizations as examples.

“We really haven’t had an integrated focused strategy that pulls together all those players,” he said.

With better data tracking the issue, veteran organizations hope it will inspire a national dialogue that tackles the issue head on -- perhaps in the same way the country rallied behind gay teen suicide with the “It gets better” campaign, Rieckhoff said.

“We’ve got to figure out how to get Silicon Valley and Hollywood and Wall Street and all these other players not directly involved in our community” riled up about the cause.